Radiotelegraphy.



C. HORTON.

RADIOTELEGRAPHY..

APPLICATION FILED JULY'29, 1913. 1,174,726. Patented Mar. '7, 1916.

2 SHEETS-SHEET 1.

C. HORTON.

RADIOTELEGRAPHY.

APPLICATION FILED JULY 29. 1913.

Witweooeo:

Patented Mar. 7, 1916.

2 SHEETS-SHEET 2.

' UNITED STATES PATENT OFFICE.

CHARLES HORTON, OF NEW YORK. N. Y., ASSIGNOR ONE-TENTH TO AUGUSTUS M.

HENRY, OF LABCHMONT, NEW YORK. 4

RADIOTELEGRAPHY.

' Specification of Letters Patent.

Patented Mar. 7, 1916,

Application filed July 29,1913. Serial No. 781,853.

ments in Radiotelegraphy, of which the following is a specification.

Thisinvention rel'ates'to improvements in wireless or' radiotelegraphy, and more particularly aims to provide an improved coupler or oscillation transformer for rapidly and with precision establishing a highly accurate state of resonance or tuning agreement between the frequency of the circuit including the primary coil of the transformer at the receiving station and the frequency of the radio-electric waves intercepted by the receiving stations aerial.

One ofthe objects of this invention is to provide a coupler of the above typeadapted for resonant. adjustment within a wide range of wave lengths or frequency variations.

pler and one adapted for ease and rapidity of manipulation in establishing resonance.

Another object is to provide such a coupler and one that is capable of exceedingly simple and compact construction.

Another object is to provide such a coupler and onethat is capable of inexpensive and economical manufacture.

Another object is to provide such a coupler and one wherein-the primary and secondary coils of the transformer may be electrically coupled, and preferably by induc-.

tion only, whereby there is obviated any danger of short-circuiting any of the coilwindings or otherwise accidentally interfering with the efliciency of the tuning.

An important object of this invention is totally to eliminate slider, switch or other imperfect contacts, and to 'substitute'therefor permanent and low-resistance connections throughout.

' Other objects and aims of the invention,-

more or less broad than those stated above,

Another object is to provide such a couto each other as scribed,

In the accompanying drawings, which are to be taken as a and wherein there sible embodiments present preferred: view of one of said embodiments; Fig. 2 is a side elevation of the parts shown in Fig. 1; Fig. 3 is an end elevation, parts disclosed in Figs. 1 and 2, and looking toward the left; Fig. 4 is a diagrammatic view of the windings carried by the cylinders 18 and-19 shown in Fig. 1, disclosing the winding 18 (carried by the cylinder 18) opposed in direction to the winding 19 (carried by the cylinder 19), which cylinders 18 and 19, adjustable with reference hereinafter described, are here assumed to carry, say, the primary coil of the transformer, the complete primary coil of the transformer being here thus comprised of the windings 18 and 19' arranged in series; Fig. 5 is a diagrammaticview of the windings carried by the cylinders 20 and 21 shown in Fig. 1, disclosing the winding 20 (carried by the cylinder 20) opposed in direction to the winding 21' (carried by the cylinder 21), which cylinders 20 and 21, adjustable with reference to each other as hereinafter deare here assumed to carry, say, the secondary coil of-the transformer, the complete secondary coil of the transformer being here thus comprised of the windings 20 and 21 arranged in series; Fig. 6 is a side elevation of another'of said embodiments;

part of this specification, are disclosed various posof this invention as at Figure 1 is a top plan showing the Fig. 7 is an end elevation of the parts shown in Fig. 6, and looking toward the left; Flg. 8 is a diagrammatic view of the windings carried by the disks 22 and 23 shown in Fig. 6, disclosing the winding 22' (carried by the disk 22) opposed in direction to the winding 23' (carried by the disk 23), which disks 22 and 23, adjustable with reference to each other as hereinafter described, are here assumed to carry, say, the primary coil of the transformer, the complete primary COll of the transformer being here thus comprised of the windings 22 and 23 arranged in series; Fig. 9 is a diagrammatic view of the windings carried "by the disks 2& and 25 shown in Fig. 6, disclosing the winding 24 (carried by the disk 24:) opposed in direction to the winding 25 (carried by the disk 25), which disks 2e and 25, adjustable with reference to each other as hereinafter described, are here assumed to carry, say, the secondary coil of the transformer, the complete secondary coil of the transformer being here thus comprised of the windings 24- and 25 arranged in series; Fig. 10 is a side elevation of another of said embodiments; Fig. 11 is an end elevation of the parts shown in Fig. 10, and looking toward the left; Fig. 12 is a side elevation of another of said embodiments; Fig. 13 is an end elevation of the parts shown in Fig. 12, and looking toward the left; Fig. 1% is a side elevation of another of said embodiments; Fig. 15 is a detail view in elevation, showing certain parts and a method of mounting the same utilizable in connection with certain of said embodiments; Fig. 16 is a detail view in front elevation, showing the parts disclosed in Fig. 15; Fig. 17 is an enlarged detail view of certain of the parts disclosed in Fig. 16; Fig. 18 is a diagrammatic view of the windings 18' and 19' of Fig. 4 (or 20 or 21 of Fig; 5, or 22' and 23 of Fig. 8, or 24'. and 25 of Fig. 9), showing said windings not opposed in direction but still connected in series; Fig. 19 is a diagrammatic view of the windings 1.8 and 19 of Fig. 4 (or 20 and 21 of- Fig. 5, or

22 and 23 of Fig. 8, or 24' and 25' of Fig.

9), showing said windings opposed in direction and connected in parallel; and Fig. 20 is a diagrammatic view of the windings 18 and 19 of Fig. 4 (or 20 and 21 of Fig. 5, or 22 and 23 of Fig. 8, or 2i and 25 of Fig. 9), showing said windings not opposed in direction and still connected in parallel.

Similar reference characters refer to similar parts throughout, the several views of the drawings.

In thereception of wireless messages, the coupler or oscillation transformer plays a most important part. In fact, without this instrument, uninterrupted. communication monious alternating currents, each current corresponding in frequency to the number of V.

oscillations characteristic of the approprlate train of waves. If the aerial, however, is connected to an oscillation transformer, even of the types' which have been proposed and utilized heretofore, a selection is possible. The oscillation transformer or conpler that is well-known in the art is merely an arrangement of two independent circuits, one inductively adjustable with reference to the other and each adjustable as to self-in-- ductance. Before taking up the description of the present invention, then, it should be understood that in utilizing a coupler, the primary and the secondary coils must be so adjusted that the natural frequency of the circuit including the primary coil and the antennae and the natural frequency of the secondary circuit are each substantially the same as the frequency of the incoming waves which are intercepted by the aerial, for it is then (z'. 0. when these three frequencies agree) that the greatest flow of current is produced in the secondary circuit, 71. 6., the circuit including, for the purposes of the present discussion, the receiving apparatus. When such a state of resonance is established, and the mutual inductance or coupling is sufficiently weakened (as by widely separating the primary and the secondary coils), a train of waves coming from a particular sending station is isolated and made individually distinct from any signals from other sending stations which, traversing the aerial simultaneously, would otherwise set up interference and conflict.

This invention comprises such an improvement over oscillating transformers or couplers as heretofore proposed that it permits of absolutely accurate and continuous adjustment of the inductance of both the primary and secondary coils of the transformer at the receiving station, not only with reference to the two coils as a combination, but with reference to each coil 1 individually; so that the receiving apparatus may be easily and rapidly tuned up to a particular wave frequency characteristic of a particular distant sending station with which it is desired to communicate. To vary the mutual inductance of the transformer by varying the relation of the two coils as a combination, I here illustratively arrange means for separating the coils in greater or less degree, since one well-known method of varying this mutual inductance consists in varying the position of one coil with respect to the other; and to vary the self-inductance of each coil individually I ,here illustratively arrange each coil so that certain of the windings of each coil may neutralize in varying degrees certain other windings of the same coil, as exemplified by the constructions of Figs. 1 to 9, inclusive,

- or illustratively arrange means for spacing certain of the windings of each coil in varying degrees from certain other windings of the same coil, as exemplified by the constructions of Figs. 10 to 17, inclusive.

Now referring particularly to Figs. 1 to 5- inclusive, the reference numeral 26 represents a suitable bed-plate adapted to carry as shown a pair of end standards 27, a center bracket 28, and a plurality of binding posts 29. Fixedly mountedwithin the bracket 28 is a cylinder 19 carrying a face-plate 30. Mounted as shown withinthis face-plate 30 are a pair of horizontally extending rods 31. A second cylinder 18 carries a faceplate 32 as shown, within which are fixedly mounted a plurality of transversely arranged sleeves 33, and these sleeves are adapted to coiiperate in the manner disclosed with the rods 31 and the central rod 34 which extends longitudinally of, the bedplate 26 and is terminally mounted in the.

standards 27. It should be noted that the cylinders 18 and 19 are tubular, and that the cylinder 18 is of sufiiciently greater diameter than the cylinder 19 to capacitate the former for travel longitudinally of the rods 31 and 34 to overlap and encompass in any desired degree said cylinder 19. A third cylinder 20 carries a face-plate 35 as shown, within which are mounted as illustrated a pair of horizontally extending rods 36 and a transversely arranged and centrally located sleeve 37. Sleeve 37 is adapted to cooperate in the manner disclosed with central rod 34for the adjustment of cylinder 20 longitudinally of said rod. It should benoted that the bracket 28 is transversely apertured by means of the circular opening 38 as shown in Fig. 3, this opening being of a suiiiciently large diameter to capacitate the cylinder 20 for travel longitudinally of the rod 3 1 to become overlapped by and enter in any desired degree thecylinder 19. A fourth cylinder 21 carries two end face-plates 38 and 39 as shown within each of which are fixedly mounted a plurality of transversely arranged sleeves 40, and these sleeves are adapted to cooper- 1 ate in the manner disclosed with the rods the former for travel longitudinally of the rods 36 and 34: to overlap and encompass in any desired degree said cylinder 21.

The cylinder 18 carries in any suitable manner a predetermined number of turns of a winding (the winding 18 of Fig. 4) which forms a part of the primary coil of the transformer, and cylinder 19 carries in any suitable manner a predetermined number of turns of the winding (the winding 19 of Fig. 4) forming the remaining part of the primary coil of the transformer. From the diagrammatic disclosure of Fig. 4, it will be seen that the windings 18 and 19' are here arranged in series, but with the latter opposed in direction to the former. Suitable connecting conductors are shown at 41 in Fig; 4, and these conductors are preferably of suiiicient' length and flexibility to permit of as great an overlap of cylinder 19 by cylinder 18, without disintegrating the primary coil during the manipulation, as is desired. Cylinders 18 and 19, then, may be thought of as a plurality of relatively movable and separable supports for the unitary primary coil of the transformer.

The cylinder 20 carries in any suitable manner a predetermined number of turns of a winding (the winding 20 of Fig. 5) forming a part of the secondary coil of the transformer, and cylinder 21 carries in any suitable manner a predetermined number of turns of the winding (the winding 21 of Fig. 5) forming the remaining part of the secondary coil of the transformer. From the diagrammatic disclosure of Fig. 5, it

will be seen that the windings 20' and 21 are arranged in series, but with the latter opposed in direction to the former. Suitable connecting conductors are shown at 4 2 in Fig. 5, and these conductors are preferably of sufficient length and flexibility to permit of as great an overlap of cylinder 21 by cylinder 20, or of cylinder 20 by cylinder 19, without disintegrating the secondary coil during the manipulation, as is desired. Cylinders 20 and 21, then, may be thought of as a plurality of relatively movable and separable supports for the unitary secondary coil of the'transformer.

Having thus described this embodiment of this invention, the operation thereof,

receiving apparatus to the frequency of the waves issuing from the distant sending station with which it is desired to communicate. The operator aforesaid first suitably varies the self-inductance of each of the-primary and secondary coils. One method of varying the inductance of a conducting coil, as is well-known, is to vary the effective number of turns therein; and in the present in-.

stance this is accomplished in the case of the primary coil by adjusting the cylinder 18 to overlap in any degree'the cylinder 19, for the winding on the cylinder 18 which overlaps the winding on the cylinder 19 is opposite in direction to the winding on said cylinder 19 and therefore the overlapping turns neutralize each other and themselves have no inductive effect, and thus vary the self-inductance of the entire primary coil; and in the case of the secondary coil by adjusting the cylinder 20 to overlap in any degree the cylinder 21, for the winding on the cylinder 20 which overlaps the winding on the cylinder 21 is opposite in direction to the winding on said cylinder 21 and therefore the overlapping turns neutralize each other and themselves have no inductive efiect and thus vary the self-inductance of the entire secondary coil. Having adjusted, in accordance with the foregoing principles, the self-inductance of the primary coil and the self-inductance of the secondary coil, the mutual inductance of the combination is next adjusted (in the present instance by physically separating to the proper degree the adjusted primary coil and the adjusted secondary coil), to the end that the electrical connection between the primary and the secondary coils is so weakened that any current in the antennae not in resonance with both the primary and secondary circuits will be unable to produce any appreciable effect upon the secondary circuit.

Now referring particularly to Figs. 6 to 9 inclusive, it will be seen that the bed plate 26 and the standards 27 are provided. A central bracket 43 supports vertically a disk 23. A vertically-arranged disk 22 is fixedly mounted upon a horizontally extending rod 44, which rod is slidably supported within a sleeve 45 carried by the left-hand standard 27 and which rod carries at its other end a finger-piece 46. A- vertically arranged disk 25 is fixedly mounted upon a horizontally extending sleeve-rod 47, which sleeve-rod is slidably supported within a sleeve 48 carried by the right-hand standard 27 and which sleeve-rod carries at its other end a fingerpiece 49. A verticallyarranged disk 24 is mounted upon a rod 50 slidably supported within sleeve-rod 47 and carrying at its other end a finger-piece 51. Disks 22 and 23 may be thought of as a plurality of movable supports for the primary coil of the transformer, and here one-half of said coil, to wit, the winding 22 shown in Fig. 8, is suitably carried by the disk 22, and the other half of said coil, to wit, the winding 23, shown in Fig. 8, is carried in any suitable manner by the disk 23; the windings 22 and 23 here being arranged in series and 0p posed in direction as disclosed. And the disks 24 and 25 may be thought of as a plurality of relatively movable supports for the secondary coil of the transformer, and here one-half of said coil, to wit, the winding 24 shown in Fig. 9, is suitably carried by the disk coil, to wit, the winding 25 shown in Fig. 9, is carried in any suitable manner by the disk 25; the windings 24' and 25 here being arranged in series and opposed in direction as disclosed. -The conductors 52 shown in Figs. 8 and 9 are preferably of a suitable length and flexibility to permit of the varying adjustments of disks 22, 24 and 25 below described. Having thus described this embodiment of this invention, the operation thereof, which should largely be obvious, may now be understood. The relatively movable elements of the coupler, that is, the disks 22, 24 and 25, are rapidly manipulated by the operators utilization of the finger-pieces 46, 49 and 51, until said disks have been so set with relation to each other and with relation to the fixed disk 23 that the proper inductive combination is attained by the transformer to tune up the local receiving apparatus to the frequency of the waves issuing from the distant sending station with which it is desired to communicate. It will be seen here, too, that, as described in connection withthe description of the operation of the embodiment of this invention disclosed in Figs. 1 to 5 inclusive, not only is the inductance selectively variable by virtue of separating more or less the primary coil as a unit from the secondary coil as a unit (that is, by varying the separation of the two disks 24 and 25, as a group, say, from the two disks 22 and 23 as a group), but also by more or less separating the windings of each coil (that is, by varying the separation of the disk 22 from the disk 23', and by varying the separation of the disk 25 from the disk 24).

Referring now particularly to the embodiment disclosed in Figs. 10 and 11, a base 53 is provided with a pair of standards 54 adapted to support as shown a fixed shaft 55. Base 53 supports a transverse vertical plate 56, Within which plate is fixedly carried as shown a winding-supporting disk 57. Similar disks 58, 59 and 60 are fixedly supported each terminally as shown of a separate arm 61. Each arm 61 is here an integral part of a separate bell-crank lever, the other arm of each of which bell- 24, and the other half of said crank levers is established by an arm 62 terminally carrying a finger-piece 63, and each of which bell-crank levers carries as shown a hub-portion adapted to be loosely sleeved about the fixed shaft 55; from which it will be seenthat by manipulating the finger-pieces 63 as desired the windingsupporting disks may to overlap each other -in a possible multitude of combinations. -An expansile spring 64, coiled about the shaft 55, and restrained at one end against a sleeve 65 loosely carried by the shaft 55, serves to maintain the said hub-portions of said bell-crank levers in proper frictional engagement to secure their retention of any location to which they may have been shifted by the operator. An auxiliary base 66 is also shown, this base being here provided with the undercut slot 67 as shown. A presser-plate 68 carries a depending stem 69 which is mounted within said base 66 as shown, and to the lower end of this stem is pivotally connected one end ofa bell-crank lever 70, this lever 70 being intermediately pivoted as at 71 to the lip 72 carried by said base 66: The so-called bell-crank -lever 70 is really, as illustrated in Fig. 10, a crank shaft arrangement, the rotatablerod 71 fixedly carrying at'difl'erent points in its length the two arms of the bell-crank lever 70. lever 73 is fixedly pivoted upon the base 53 as shown,'andis bifurcated at each end,. one bifurcation to coeperate with the pin 7 carried by the sleeve 65 and the other bifurcation to cooperate with the pin 75 carried by the short I 58. being preferably suitably flexibly con-,

arm of the bell-crank lever 70. An exp'ansile spring 76 is here coiled aboutthe stem 69 and interposed between the presser-plate 68 and the base 66 as illustrated. A retractile spring 77 connects ,as shown the plate 56 and'the disk 60, as an exemplification of a possible utilization of springs or counterweights for compensation purposes. The disk 58here may carry in any suitable manner a predetermined number of turns of a winding similar, to the winding 22 of" Fig. 8, andthe disk 59 may carry in any suitable manner a predetermined number of. turns of a winding similar to the winding 23of Fig. '8, the winding upon disk nected to the winding upon disk 59 adjacent the location of the connector 52 shown in Fig. 8, whereby disks 58 and 59, although relatively movable, coiiperate to support the complete primary coil'of the transformer. The disk 57 here may carry in any suitable manner a predetermined number of turns of a winding similar to thewinding24 of Fig. 9, and the disk 60 may carry in any suitable manner apredeterminednumber of turns of a winding similar to the winding '25 of Fig. 9, e winding upon disk 57 be.

be variously adjusted ing preferably suitably flexibly connected to the winding upon disk 60 and the windings upon disks 57 and 60 being similarly connected to the adjacent conductors in the .circuit as via the conductors 52 shown in .erator rests the palm of his hand upon press'er-plate 68,v and thereby, through the rocking of the bell-crank lever and the lever 73, moves thesleeve 65 to the right and compresses the spring 64 and thus releases the frictional engagement normally maintained between the hub-portions carried by the disk-supporting bell-crank levers; and easy manipulation of the fingerpieces 63 is then made possible. Upon the operator setting the disks 58, 59 and 60 so that they overlap each other and the fixed disk 57 in the proper degrees and relations to set up within the transformer the inductive combination requisite to accurately tune up as desired, a release of the pressure of the operators palm upon the presser- 1 plate 68 immediately frictionally lockseach of the disks 58, 59 and 60 into its properly adjusted location. It will be seen here, too, that, as. described in connection with the description of the operation .of the embodiments of this invention disclosed in Figs. 1 to 5 inclusive, not' only is the inductance selectively variable by virtue of separating I more or less the primary coil as a unit from integrallycarries as shown the pair of side standards 27. These standards integrally carry a vertically and transversely supported plate 78. ,Plate 78 supports as shown a fixed winding-supporting disk 79, Similar disks 80, 81 and 82 are each fixedly sup 'ported by a separate arm 83 as shown.

Each arm 83 is .here an' integral part of a which bell-cra-nk'lever is established by an 7 separate bell crank lever, the other arm of arm 84 terminally carrying a finger-piece 85, and each of which bell-crank levers carries a shown a-hub-portion adapted to be loosely sleeved about the fixed shaft 86; from which it will be seen that by-manipulating the finger-pieces 85 as desired the winding-supporting disks maybe variously adjusted to overlap each other 1n a possible multitude of combinations. An expansile spring 87, coiled about the shaft 86 and restrained at one end against the right-hand standard 27 and at its other end against the sleeve 88 loosely carried by the shaft 86, serves to maintain the said hub-portions of said bellcrank levers in proper frictional engagement to secure their retention of any location to which they may have been shifted by the operator. A retractile spring 89 connects as show-n the arm 83 and the plate 78, as an exemplification of a possible utilization of'springs or counter-weights for compensation purposes. Parts analogous to the auxiliary base 66 and its associated parts shown in Figs. 10 and 11, are not disclosed in connection with this embodiment of this invention, but it should be understood that said base and its said associated parts, or. an equivalent or substitute device or devices, could be within the scope of this invention utilized in connection with any of the various possible embodiments thereof. The disk 80 here may carry in any suitable manner a predetermined number of turns of a wind-' ing similar to the winding 22' of Fig. 8, and the disk 81 may carry in any suitable manner a predetermined number of turns of a winding similar to the winding 23' of Fig.

8, the winding upon disk 80 being preferably suitabl connected to the winding upon disk 81 adjacent the location of the connector 52 shown in Fig. 8, wherebydisks 80 and 81. although relatively movable. cooperate to support the complete primary coil of the transformer. The disk 79 here may carry in any suitable manner a predetermined number of turns of a winding similar to the winding 24 of Fig. 9, and the disk 82 may carry in any suitable manner a prede-' termined number of turns of a winding similar to the winding 25 of Fig. 9, the winding upon disk 79 being preferably suitablvflexiblv connected to the winding upon disk 82 and the windings upon disks'79 and 82 being similarly connected to the adjacent conductors in the circuit as via the connectors 52 shown in Fig. 9, whereb disks 79 and 82, althou h relatively movable, cooperate to support the complete secondary coil of the transformer. Having thus described this embodiment of this invention. the operation thereof, which should largel be obvious, may now be understood. The relatively movable elements of the cou ler. thatis. the disks 80, 81 and 82 are rapidly manipulated other and the by the operators utilization of the fingerpieces 85. Upon the operator setting, said disks 80, 81 and 82 so that they overlap each fixed disk 79 in the proper degrees and relations to set up within the transformer the inductive combination requisite to accurately tune up as desired, it will be seen here, too, that, as described in connection with the description of the operation of the embodiment of this invention disclosed'in Figs. 1 to 5 inclusive, not only is the inductance selectively variable by virtue of separating more or less the primary coil as a unit from the secondary coil as a unit (that is, by varying the separation of the two disks 80 and 81 as a group, say, from the two disks 79 and 82 as a group), but also by more or less separating the windings of each coil (that is, by varying the separation of the and by varying the separation of the disk 82 from the disk 79).

7 Referring now particularly to the embodiinent disclosed in Fig. 14, it will be observed that there are disclosed the bed-plate 26, the standards 27 ,the bracket 28, the supporting rod 34, the rods 31 and 86, the fixed cylinder 19, and the movable cylinders 18, 20 and 21. In this embodiment, for purposes of illustration, the cylinders 18 and 19 are assumed to carry the windings 18' and 19' respectively, as illustrated in Fig. 4, and as described in connection with the embodiments of this invention illustrated in Figs. 1 to 5 inclusive, and the cylinders 20 and 21 are assumed to carry the windings 20 and 21 respectively, as illustrated in Fig. 5 and described in connection with the embodiment of this invention illustrated in Figs. 1 to 5 inclusive. Bed-plate .26 has suitably mounted in the extension 90 thereof a suitable shaft 91 adapted to pivotally support the bell-crank levers 92, 93 and 94. Each bell-crank lever carries as shown a finger-piece 95. Bell-crank lever 92 is pivotally connected as shown to one end of a link 96, the other end of which link is fastened as shown to movable cylinder 18, said link being preferably of a suitable flexible material. A similar link 97 similarly connects bell-crank lever 93 and movable cylinder 20, and a similar link 98 similarly connects bell-crank lever 94 and movable cylinder 21. Retractile springs 99 connect as shown, onethe left-hand standard and the cylinder 18, another the bracket 28 and cylinder 20,

and the other cylinders 20 and 21, as an exemplification of a possible utilization of springs or counterweights for compensation purposes. Havingthus described this embodiment of this. invention, the operation thereof, which should largely be obvious, may now be understood. The relatively movable elements of the coupler, that'is, the

- ders 18, 20 and 21 overlap each other and cylinders 18, 20 and 21, are rapidly manipulated in a manner similar to the hereinbefore described manipulation of the cylinders 18, 20 and 21 shown in Figs. 1 and 2, but by the operatorsutilization of the finger-pieces 95, to the end that said cylinthe fixed cylinder 19 in the proper degrees and relations to set up within the transformer the inductive combination requisite to accurately tune up as desired.

Referring nowv particularly to Figs. 15,

16 and 17, there is disclosed an alternative method of mounting the finger-pieces 95 shown in Fig. 14 wherein a presser-plate or the like similar to the presser-plate 68 shown in Fig. 10 may be utilized to release a clutch, rather than a frictional, engagement between the bell-crank levers which, mounted upon a suitable shaft 100 mounted in suitable standards 101, carry the finger-pieces 95. This is here illustratively accomplished by providingan auxiliary shaft 102, mounted within said standards 101 as shown, and adapted for the sleeving slidably thereon of an extension 103 carried integrally by a clutch member 104 slidably sleeved on shaft 100. As shown best in Fig. 16, a clutch member 104 is interposed to the right of each of the bell-crank levers 94, 93 and 92. The adjacent end faces of each bell-crank lever and the clutch member to the right thereof are provided with engaging teeth asshown and as referred to by the reference numeral 105 in Fig; 17. It will be observed that with a. bell-crank lever-out of engagement with its cooperating clutch member 104, said bell-crank lever-is capable of rockirig upon its shaft 100, but that said clutch member 104, while capacitated for sliding bodily awayfrom said bell-crank lever to disengage its clutch, is yet restrained from any rotation about the shaft 100, but is, on the contrary, keyed in place by the sleeving [engagement of its extension 103 with the shaft 102. An expansile spring 106 is coiled about the shaft 102 as shown and tends to maintain each clutch member 104 in normal clutch engagement withits proper bellcrank lever and thereby prevent any manipulation of said finger-pieces 95 until the operation of suitable releasing means, and to lockany or all of said cylinders 18, 20 and 21 in their then adjusted position or positions upon said'releasing means becom in ineffective.

gt will thus be seen that there has been provided an improved coupler or oscillation transformer for accomplishing the various ends and objects above stated, and one that is particularly capacitated for rapidity and precision in attaining a state of resonance; and that an important step forward has been 'disclosedwhich is resident in the fact that all slider, switch or other movable and imperfect contacts are dispensed with. While this is accomplished here in part by mounting the complete primary coil of the transformer so that various windings forming parts of the unitary primary coil are each mounted upon a separate support one of which is movable with relation to the other, and alsoby mounting the complete secondary coil of the transformer so that various windings thereof forming parts of the unitary secondary coil are each mounted upon a separate support one of which is movable with relation to the other, it should be understood that the disclosures herein are merely illustrative ofthe general theory of this invention, and that while throughout the embodiments one winding of either a primary or a secondary coil is assumed to be so manipulated with reference to another winding of said coil as to vary the self-inductance of' the coil by neutralizing the inductive effect of turns of either or both of said windings, any other method of varying the self-inductance of a coil of atransformer during the maintenance/of said coils initial and permanent current-conducting characteristic is contemplated, and that, while the neutralization, as aforesaid, of certain of the turns of either the primary or secondary coil has been illustratively disclosed in Figs. 4, 5, 8 and 9- as having been accomplished by arran in the two illustrated windin s of g a g while the embodiments herein disclosedhave been described 1n connection w1th the r utilization as a recelving instrument, it is obvious that they can with great advantage be utilized for sending.

Inasmuch as many changes could be madein the' above construction, and many apparently widely different embodiments of my invention could be made without departing from'the scope thereof, it is intended that all matter contained in the above description or;shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense. It is also to .be understood that the-language used in the following claims is intended to cover all the generic and specific features of the inventlon herein described and all statements of the scope of-the invention which, as a matter 7 of language, might be said to fall therebetween.

Having described this invention, what I claim as new, anddesire to secure by Letters Patent, is:

1. In a device of the class described, a primary coil including a plurality of relatively movable sub-divisions and a fixed subdivision and each sub-division including a plurality of windings, and a secondary coil including a plurality of relatively movable sub-divisions and each sub-division including a plurality of windings, each of said sub-divisions being separately and independently movable relatively of said fixed sub-division.

2. In a device of the class described, a primary coil including a plurality of subdivisions and each sub-division including a plurality of windings, a secondary coil including a plurality of sub-divisions and each sub-division including a plurality of windings, and means adapted independently to vary the individual location of merely any one of three of said sub-divisions relatively of the location of a fourth.

3. In a device of the class described, a primary coil including a plurality of relatively movable sub-divisions and each subdivision including a plurality of helicoidal windings, and a secondary coil including a plurality of relatively movable sub-divisions and each sub-division including a plurality of helicoidal windings, one of said sub-divisions being mounted on a fixed support and three of said sub-divisions being separately and independently movable relatively of said fixed support.

4. In a device of the class described, a primary coil including a plurality of relatively movable sub-divisions and each subdivision including a plurality of helicoidal windings, and a secondary coil including a plurality of relatively movable sub-divisions and each sub-division including aplurality of helicoidal windings, one of said sub-divisions being mounted on a fixed support and three of said sub-divisions being separately and independently movable relatively of said fixed support; each of said sub-divisions being carried on a separate tubular support.

5. In a device ofthe class described, a primary coil including a plurality of relatively movable sub-divisions and each subdivision including a plurality of helicoidal windings, and a secondary coil including 'a plurality of relatively movable sub-divisions and each sub-division including a plurality of helicoidal windings, one of said sub-divisions being mounted on a fixed support and three of said sub-divisions being separately and independently movable relatively of said fixed support ;,each of said sub-divisions being carried on the outer cylindrical sur- 1 'face of a separate tubular support.

tively movable sub-di isions and each subdivision including a plurality ofhelicoidal windings, and a secondary coil including a plurality of relatively movable sub-divisions and each sub-division including a plurality of helicoidal windings, one of said sub-divisions being mounted on a fixed support and three of said sub-divisions being separately and independently movable relatively of said fixed support; each of saidsub-divisions being carried on a separate tubular support, and-one of said supports being of such an inner diameter that there may be telescoped within the same the three other supports, one of said three supports being of such an inner diameter that there may be telescoped therein the two other supports, and one of said two supports being of such a diameter that there may be telescoped therein the fourth support.

7. In a device of the class described, a primary coil including a plurality of relatively movable sub-divisions and each subdivision including a plurality of helicoidal windings, and a secondary coil including a plurality of relatively movable sub-divisions and each sub-division including a plurality of helicoidal windings, one of said sub-divisions being mounted on a fixed support and three of said sub-divisions being separately and independently movable relatively of said fixed support; each of said sub-divi-.

sions being carried on a separate tubular member, and one of said supports, be ng of such an inner diameter that them may be telescoped within the same the three other supports, one of said'three supports being of such an inner diameter that there may be telescoped therein the two other supports; and one of said two supports being of such a diameter that there may be telescope'd therein the fourth support; and means for separately and independently moving any one of said movable sub-divisions and its support relatively of said fixed sub-division and its support, said means including a plurality of instrumentalities each manipulable by a fingerof the operator.

8. In a. device of the class described, in combination, a support having a spiral inductance wound thereon, a second support having a spiral inductance wound thereon, a third support having a spiral inductance wound thereon and a fourth support having a spiral inductancethereon, two of said supports each carrying aSub-d1V1S1011 of a primary coil and two other of said supports three of said supports being separately and independently movable relatively of said fixed support.

9. In a device of the class described, in combination, a support having a cylindricalspiral inductance wound thereon, a second support having a cylindricalspiral-inductance wound thereon; a third support having a cylindrical spiral-inductance wound thereon and a fourth support having a cylindrical spiral-inductance wound thereon, two of said supports each carrying a sub-division of a primary coil and two other of. said supports each carrying a subdivision of a secondary coil, one of said supports being fixed 15 and three of said supports being separately and independently movable relatively of said fixed support.

In witness whereof I have hereunto signed my name in the presence of two witnesses. CHARLES HORTON. In the presence of A. M. HENRY, ALDA L. MILLER. 

